There has been a lot of posts on what is new in SCCM 2012 . In this Post I will try to Divide the Diffrence in the two versions from the Design and Implementation point of view and from Administration point of View :
From Design and Implementation Point of View :
1. Simplification in Terms of Hierarchy : Let me explain this . In SCCM 2007 if we wanted to manage a group of 300 users over a avaregae link we would have used a Secondary Point but in SCCM 2012 We would use a Distribution point rather than going for Secondary site . This is because Microsoft has added features like Throttling and Scheduling in the Distribution Points in SCCM 2012.
2. Role Based Access Control : In SCCM 2012 Many a times the reason for using additional Primary site was to saggrigate set of duties like x set of admins should have access of deploying packages only , certain set of users should manage Desktops only and not servers. To achieve this in SCCM 2007 was tough and in some cases impossible . But now with SCCM 2012 RBAc you can manage all this very easily .
3. Less USe of CAS : You will find that you will hardly need a CAS unless your user base is very high
4. Active Directory Forest Discovery : This is a new feature that is available with SCCM 2012 Only . This can be used to manage Multiple forests Environment.
FROM Admin Point of View :
1. User Centric : SCCM 2012 is user centric . I will make this easy to understand . Let us say that you have users in your company who use a Laptop, Desktop , Ipad , A Windows based phone at the same time . Let us say that you want a software to be available on all these devices for these users so in SCCM 2012 you will distribute this software to this user rather than distributing it to his 4 systems in SCCM 2007.
2. Application Catalog at User End : Now users in SCCM 2012 will have access to a small website from which they can use which software they want on their machine ( provided Admin has given them the access to have this software).
3. There is no reprting point in SCCM 2012 as it was there in SCCM 2007 . We have only SSRS in SCCM 2012.